The effect of osmotic potential on anther culture in spring wheat (Triticum aestivum)

This study was conducted to determine the effect of osmotic potential in a modified 85D12 medium on both callus induction and plant regeneration in the anther culture of two wheat genotypes, cv. Chris and cv. Pavon. Altering the medium osmotic potential by changing the carbohydrate source and concentration or by adding a non-metabolized osmoticum appeared to have the greatest potential for improving anther-derived green plant production. The medium osmotic potentials were varied (-0.67 to –2.30 MPa) by altering sucrose and PEG concentration. Both osmotica affected callus production, with –0.9 to –1.4 MPa media producing the most calluses. Callus production depended on genotype and osmoticum. Only PEG concentration affected green plant regeneration. The greatest number of green plants (11.5 plants per 100 anthers in cv. Chris) was obtained with 0.0125 M of PEG. This experiment suggested that a low level of PEG in the medium was beneficial for producing green plants from wheat anthers.     

Growth and yield of six short varieties of spring wheat derived from Norin 10 and of two European varieties

Five short varieties of spring wheat derived from Norin 10: Lerma Rojo 64A (R), Penjamo 62 (P), Sonora 64 (S), Mexico 120 (M), and an unnamed selection obtained from Mexico (X), had grain yields equal to, or only slightly less than those of the taller European spring varieties Kloka (K) and Jufy I (J). Yields ranged from 500 to 580 g/m² of dry matter. The short variety NBJ115 (N) was severely infected with yellow rust and yielded only 290 g/m². Total dry weight (excluding roots) of the short varieties was less than of J and K; hence grain accounted for 49 % of the total for the short varieties and 42 % for J and K. Most of the short varieties had fewer ears than the tall ones because sowing difficulties and poor germination produced fewer plants. The relative yields of X, P, R and S seemed to be correlated with their plant and ear densities. Leaf area duration after flowering (D), based either on total green area or on green area above the flag-leaf node only, was less for the short varieties than for J and K. The apparent mean efficiency of this area in grain production (grain yield divided by D) was 50% greater for the short than for the tall varieties. The height of the short varieties ranged from 43 cm (M) to 79 cm (N). K was 92 cm and J 97 cm tall. Differences in height depended on the lengths of the top four internodes and not on number of internodes. Main shoots of all varieties produced seven or eight leaves. All varieties initiated spikelets 45–48 days after sowing. The short varieties flowered 103 days and matured 155 days after sowing; J and K flowered and matured about 1 week earlier.     

Solid-stemmed spring wheat cultivars give better androgenic response than hollow-stemmed cultivars in anther culture

Solid-stemmed spring wheat cultivars (Triticum aestivum L.) are resistant to the stem sawfly (Cephus cinctus Nort.) and lodging. Anthers of 24 spring wheat cultivars with varying content of pith in the stem were used in the experiment. All were classified into three groups: solid, medium–solid and hollow stems. There was considerable influence of the cultivar on callus formation and green plant regeneration. The highest efficiency of green plant regeneration (24%) was observed for the solid-stemmed AC Abbey cultivar. There was no regeneration from the explants of four cultivars: CLTR 7027, Alentejano, Marquis and Bombona. Principal component analysis showed no differences between the cases under observation (callus induction and green plant regeneration) in their response to pre-treatment temperatures (4 and 8°C). The examination of the effects of various auxin types in the induction medium on callus formation and green plant regeneration revealed that the strongest stimulation of these processes was observed in the C17 medium with 2,4-D and dicamba. The efficiency of callus formation and green plant regeneration was greater in solid-stemmed cultivars than in hollow-stemmed cultivars.     

Immature embryo and anther culture of chromosome addition lines of rye in chinese spring wheat

Significant variation among Chinese Spring wheat (Triticum aestivum L.) and a set of seven addition lines in which chromosomes from rye (Secale cereale L.) were incorporated into the Chinese Spring background was observed for callus formation and plant regeneration from anther cultures and for plant regeneration from immature embryo cultures. Callus initiation from immature embryo cultures was uniformly high. Rye chromosome 4 contains factors which significantly increase both anther culture responses relative to Chinese Spring. Rye chromosomes 6 and 7 both contain positive factors for regeneration from immature embryo culture. While no correlation was found between anther culture and embryo culture responses, a positive correlation was observed between the two anther culture response variables.     

The improvement in regenerated doubled haploids from anther culture of wheat by anther transfer

This study was conducted to determine the most suitable method of regeneration by comparing two approaches: transfer of anthers (with and without embryo-like structures) to regeneration conditions after a period of two to four weeks on induction medium (= anther-transfer treatment) and transfer of embryo-like structures to regeneration conditions after five to eight weeks on induction medium. The early transfer of anthers brought about a significant reduction in the number of embryos formed, but nevertheless significantly improved the frequency of plant regeneration. Combining an optimal date of anther transfer with the early addition of colchicine to the induction medium (100 mg l⁻¹ for 1 and 3 days) led to an increase in the number of doubled haploid regenerants. The results indicate that transferring the anthers after 28 days and adding 100 mg l⁻¹ colchicine to the induction medium on one day only caused a significant improvement in the ability of green plants to regenerate (7.0 compared to 0.50) as well as in chromosome doubling (success index: 4.0 compared to 0.33). This revised version was published online in August 2006 with corrections to the Cover Date.     

甘、青两省春小麦遗传多样性演变

对甘、青两省自20世纪40年代以来生产上曾大面积应用的200多个春小麦地方品种和育成品种资料进行了分析,结果表明,19个形态性状,5个农艺性状和2个品质性状都存在着广泛的遗传多样性,虽然育成品种农艺性状和品质性状的遗传多样性总体上大于地方品种,但是从20世纪60年代开展春小麦杂交育种工作之后,育成品种形态性状,农艺性状和品质性状遗传多样性呈下降趋势,评价育种对小麦遗传多样性的影响,不能足将地方品种和育成品种的遗传多样性作一简单比较就得出结论,而是应该在遗传多样性演变的动态过程中去研究。     

两春小麦品种竞争能力、水分利用效率及产量关系的研究

用盆栽方法测定了2个春小麦品种－地方品种和尚头与现代品种陇春－8275在5个土壤水分梯度下,单、混播时的水分消耗、水分利用效率、竞争能力和籽实产量。单播条件下,在极低水分条件下（12％）,和尚头有相对较高的产量,在水分条件较好时陇春－8275有较高的产量;在保持各水分处理条件下,地方品种和尚头较之现代品种陇春－8275消耗更多的水分,水分利用效率较低。混播条件下,各尚头有较高生物量、籽实产量及较强的竞争能力,竞争优势不受土壤水分的影响,其表现为高个体生物量品种较之低个体生物量品种消耗更多的水分,陇春－8275受到强烈的抑制,消耗较少的水分及较低的籽实产量。表明进化选择的是竞争能力,而非单播下的产量表现。可以预见,在小麦育种中选育具小根系的对水分弱竞争能力的品种将成为半干旱区今后育种的一个重要方法。     

Defense strategy of old and modern spring wheat varieties during soil drying

Different defense mechanisms of three spring wheat ( Triticum aestivum L.) varieties were studied by withholding watering in well-watered pots to gradually increase water deficit of plants grown in containers. The strategies of plant adaptation were divided into three phases according to the severity of drought: first, a positive defense phase that started from commencement of non-hydraulic root-sourced signals (nHRS) and ended at onset of hydraulic root-sourced signals (HRS)—the plant responded to imminent drought by decreasing stomatal aperture to lessen water loss and no membrane injury occurred. The second defense phase occurred between the onset of HRS and temporary wilting (TW), characterized by enhancement of reactive oxygen species (ROS), marked enzyme activity and increased MDA content. Mild lipid membrane peroxidation came mainly from a dynamic imbalance between free radical production and enzymatic defense reaction, which indicated that injury by ROS had not been completely repaired by increasing enzymatic activity. The third defense phase was from TW to permanent wilting (PW), the synthesis of SOD and CAT during TW could not deal with the collapse of antioxidant enzymes, and SOD and CAT activities began to decrease, which caused the excessive ROS production and thus serious membrane lipid peroxidation. The defense strategies to drought are similar among the varieties, but modern varieties LC8275 and GY602 bred after 1975 had relatively higher defense levels at all three defense phases, which suggest that modern varieties are more resistant than old ones, and artificial selection would lead to a different direction in evolution from natural selection.     

Influence of 2,4-D, IAA, and duration of callus induction in anther cultures of spring wheat

Culture media and environmental factors may significantly influence the yield of haploid plants from anther cultures. Our objectives were to identify a combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and indoleacetic acid (IAA) concentrations which produce the maximum number of haploid plants, and to evaluate the effects of duration in induction medium on calli induction, plant regeneration, and green plant production from anther cultures in spring wheat. Significant (P ≤ 0.01) plant growth regulator concentration effects (2,4-D and IAA) were observed on the number of calli, green plants and albino plants produced, and on direct plant regeneration. Addition of 2,4-D to the induction medium resulted in significantly (P ≤ 0.01) higher means for all anther culture components compared to IAA> While addition of 2,4-D significantly (P ≤ 0.01) reduced plant regeneration, it substantially increased green plant percentage at a 0.3-mg l⁻¹ concentration of IAA. Use of response functions to estimate the maximum effective 2,4-D × IAA combination implied that higher 2,4-D levels in the induction medium should be investigated, and that the optimum hormone combination differs for plant regeneration and green plant percentage. Significant (P ≤ 0.01) effects of duration on callus induction medium were observed for plant regeneration and green plant percentage.     

The inheritance of tetraploid wheat seed peroxidases

Summary Embryo and endosperm peroxidases from dry mature seeds of three subspecies of tetraploid wheat (Triticum turgidum L.) were subjected to genetic analysis. The inheritance of eight isozymes (embryo isozymes a₂, d₁, d₂, e and f; and endosperm isozymes b, d and 4) were studied in F₂'s obtained from different wheat accessions. Simple monogenic inheritance producing three banded: one null segregation and two epistatic segregations (97 and 151) were found. In the case of isozymes b, d and 4, monogenic or epistatic segregation depended on the F₂ analyzed. Segregation data indicated that at least 9 different loci would determine the peroxidase isozymes of tetraploid wheat seed, all the loci studied containing null alleles. Furthermore, several loci determining embryo peroxidases were noticed to be mutually linked. All these data are discussed in context of the inheritance of seed peroxidases in hexaploid wheat and rye.     

Genotypic features of morphogenesis in spring barley anther culture

The variability of characteristics in haploid production was assessed depending on the growth conditions for donor plants, ear pretreatment technique, and nutrient medium composition. The ranks of genotypes included in the experiment remained unchanged in terms of their in vitro ability toward androgenesis, which evidences the significant contribution of a genetic component to the general variability and demonstrates the need to investigate how genetic control of androgenesis works.     

Polymorphism and inheritance of gliadin components controlled by chromosome 6A of spring durum wheat

The gliadin composition of 78 spring durum wheat varieties has been studied by one-dimensional (Al-lactate, pH 3.1) and two-dimensional (first dimension, Al-lactate, pH 3.1; second dimension, sodium dodecyl sulfate-polyacrylamide gel) electrophoresis. Analysis of hybrids has shown that all components of the alpha zone of gliadin spectra are inherited together as blocks and are, probably, coded for by a cluster of tightly linked genes located on chromosome 6A. Fourteen variants of gliadin blocks have been identified, which can be classified into five families on the basis of component composition. All families but one have analogues among chromosome 6A-controlled blocks of bread wheat. The results indicate that some of the genome A diploid genotypes that were ancestors of durum wheats were also ancestors of bread wheats and that polyploid wheats were produced by repeated allopolyploidization events, as has been suggested earlier.     

Reciprocal effects in anther cultures of wheat hybrids

This study was conducted to determine the reciprocal effects for anther culture response in wheat (Triticum aestivum L.) using a set of 4 × 4 full diallel crosses. Both reciprocal and nuclear genetic effects were highly significant for anther culture response and useful for selection and breeding purposes. General combining ability (GCA) effects were predominant for all investigated anther culture traits. Also, significant differences for specific combining ability (SCA) effects were detected between reciprocal crosses. Although significant reciprocal differences for responding anther, callus number and green plant regeneration were recorded in some reciprocal crosses, there were no significant reciprocal differences for albino plant regeneration. The use of one parent as male or female could lead to change at the production of green plants from the F₁ hybrids and screening of inbred lines for response to anther culture, without reciprocal effects, could decrease the utilization of breeding material.     

Agronomic performance of lines derived from anther culture, maize pollination and single-seed descent in a spring wheat cross

Anther culture and maize hybridization are two frequently used techniques for doubled haploid production in wheat (Triticum aestivum L.). Information on the field performance of lines derived from these techniques is limited. This study was conducted to compare the performance of F_4:6 lines obtained by single-seed descent with lines obtained by anther culture and maize (Zea mays L.) pollination from the same cross of spring wheat, ’Chris’/MN 7529. Thirty-three lines derived from each of those techniques were evaluated in six environments for grain yield, protein content, test weight, heading date, kernel weight and plant height. Mean performance of the single-seed descent lines exceeded performance of the anther culture lines for grain yield, kernel weight and plant height with no apparent differences for grain protein content, test weight and heading date. No differences between trait means for the single-seed descent and maize pollination lines were found except for plant height. The best 5 lines from each method for grain yield, protein content and test weight were similar in performance except that the protein content was higher for the maize pollination lines than for the single-seed descent lines. Acceptable levels of agronomic performance could be found among lines from each method. Wide acceptance of the doubled haploid technique for pure line production in breeding programs may, however, be limited by the often poor efficiency of doubled haploid line production, resulting in smaller population sizes for selection of desirable traits in comparison to the single-seed descent method. Received: 31 July 1998 / Accepted: 28 November 1998     

The inheritance of diastatic power and alpha-amylase contents in spring barley

Summary Nuclei were isolated from various types of donor protoplasts and were transferred into receptor protoplasts in numerous combinations. Five percent uptake was achieved under conditions which did not interfere with viability and subsequent culture of receptor protoplasts. Methodological investigations on nuclei uptake were carried out with cereal and tobacco protoplasts. To look for biological proof of integration and replication of transferred nuclear genes, two complementing, chlorophyll-deficient, light-sensitive mutants of tobacco were used as sources of nuclei and receptor protoplasts. Ca. 5.5 × 10⁷ receptor protoplasts were cultured following transplantation experiments involving these complementing mutants and about 1.8 × 10⁷ of the resulting calli were subjected to selective conditions which discriminate against the parental types. No nuclear hybrids were detected, although in control experiments somatic hybrids were obtained by protoplast fusion. Some explanations for failure of nuclear hybrid formation are discussed together with other possible approaches for selective somatic combination of plant cell genophores.     

冬麦春播小麦穗分化阶段对低温胁迫的响应及耐寒性

以长江中下游地区引进的10个冬小麦品种为材料,在忻定盆地春播条件下,于2013-2014年研究了低温胁迫对冬小麦穗分化阶段光合作用、渗透调节物质及膜系统产生的影响,并对其抗寒性能进行综合评价.结果表明:在低温胁迫下,不同品种小麦叶片的离子渗漏率、可溶性糖和可溶性蛋白质含量均不同程度地升高,总叶绿素含量明显下降.通过主成分分析和抗寒性度量值(D值)排序,不同品种冬小麦幼穗分化期间的抗寒性为:渝麦10、扬麦20、云麦42的抗寒性较差;扬麦13、渝麦12、宁麦13的抗寒性较强且年际稳定性好,D值分别为0.665 ～0.659、0.493～0.495、0.471 ～0.583;而作为对照的宁2038、新春30分别为0.368～0.397、0.328～0.330.扬麦13、渝麦12、宁麦13的两年籽粒产量显著高于其他品种,可作为忻定盆地的引种材料.     

Evidence for microspore embryogenesis in wheat anther culture

Summary In wheat, plants may be regenerated from microspores via direct embryogenesis or organogenesis or embryogenesis from callus. Light and scanning electron microscopy were used to carefully study morphogenesis of microspore-derived plants from anther culture on modified 85D12 starch medium and to determine whether the plants were formed via organogenesis or embryogenesis. Our results indicate that plants are formed via embryogenesis from microspores. Evidence for embryogenesis included the formation of the epidermis and a suspensorlike structure (21 days after culture), followed by initiation of an apical meristem, differentiation of the scutellum, and embryo elongation. At 28 days in culture, the embryo possessed a well-developed scutellum and axis with suspensor. Embryogenesis was further confirmed by coleoptile and radicle elongation during germination when the embryos were cultured on medium supplemented with kinetin with or without coconut water. In this system, an average 67 microspores per responsive anther began cell division but only 3.69 embryos were formed per responsive anther after 6 wk. Adventitious embryos could be induced if the embryos, once formed, remained on initiation medium for 10 wk instead of being transferred to regeneration medium. Developmental stages which may be amenable to changes that could enhance plant production were identified. The potential to use this information to enhance plant production is discussed.     

Two pathways of plant regeneration in wheat anther culture

The anthers of 10 Polish winter wheat (Triticum aestivum L.) cultivars were used for the induction of androgenesis and plant regeneration. The highest rate of callus induction (9.1%) and green plant production (0.8%) was obtained with the cultivar Apollo that was chosen for histological analysis. The first androgenic division was symmetrical and occurred after 3 weeks of culture. Further divisions of newly formed cells gave rise to multicellular structures which followed two developmental pathways: callus production or direct embryo formation. Plant regeneration was observed in both pathways. Chromosome counting of plantlets regenerated showed that haploid metaphases 2n=3x=21 were the most frequent.     

Comparison of the accumulation of 137Cs and 90Sr by six spring wheat varieties

The uptake of ¹³⁷Cs and ⁹⁰Sr by six varieties of spring wheat (Triticum aestivum) was compared in field trials on land contaminated by the Chernobyl accident. All the experimental varieties are officially adopted for agricultural use in Belarus and are used in large-scale production. Under identical conditions of nutrition, the productivity of the varieties varied significantly by a factor of 1.3. The extent of ¹³⁷Cs and ⁹⁰Sr accumulation by wheat grain, quantified as the concentration ratio, differed between the varieties by as much as a factor of 1.6, for both radionuclides. There was a significant linear positive correlation between the ⁹⁰Sr activity concentration in grain and straw, and the calcium concentration. The correlation between ¹³⁷Cs and potassium was not significant. The results suggest that certain varieties of spring wheat used in normal agricultural practice accumulate less ¹³⁷Cs and ⁹⁰Sr into grain than others. Some spring wheat varieties accumulated relatively less ¹³⁷Cs, but did not accumulate less ⁹⁰Sr. One variety, Quattro, had a significantly lower uptake of both ⁹⁰Sr (for grain) and ¹³⁷Cs (for both grain and straw) than that of the other varieties tested. The reduction efficiency achieved by the use of these varieties, however, is not as high as that achieved by soil amelioration techniques in the past. Nevertheless, since there are no additional costs or production losses associated with these varieties, their use in the contaminated areas is worth considering as a simple, practical, and effective contribution to reducing the uptake of both ⁹⁰Sr and ¹³⁷Cs and allowing farmers to produce food-grade grain.